Note: Due to increased usage of SharePoint Online and OneDrive, Microsoft has taken temporary measures to ensure critical services remain available and reliable to users in remote work scenarios. There are tighter throttling limits for background migration applications such as the ShareGate migration tool as a result.
These added limits are applied on top of regular throttling during working hours only. The evening and weekend hours for the region of your tenant will not be impacted. To minimize the impact on your migration process, please follow these guidelines:
Throttling is completely normal, so if you experience it you shouldn't worry. Throttling is an essential security mechanism that ensures the service offered by your server remains healthy and responsive. It is referred to as "throttling" because it is limiting the workload coming through the server. Without this, the server could become unresponsive or even crash completely---causing service interruptions for all users.
- Throttling when running a Microsoft 365 migration
- Updating your version of the ShareGate migration tool
- The cause and effect of throttling
- Reducing the load to prevent throttling
- Significant throttling
- How we help
Throttling when running a Microsoft 365 migration
When running your Microsoft 365 migration you may get an error indicating the status code 429 Too Many Requests or 503 Service Unavailable.
These errors do not indicate that your migration has been stopped, they serve to notify you that your tenant is under a lot of pressure and therefore it cannot handle the number of requests required at the moment. You need to wait, as the ShareGate migration tool will retry the procedure until the server is ready to handle the number of requests required to proceed with the migration. You can cancel the procedure at any moment if you prefer to attempt the migration at another time.
Updating your version of the ShareGate migration tool
Since September 2019, we introduced the ShareGate migration tool Azure app, which can effectively reduce throttling on tasks between the ShareGate migration tool and Microsoft 365. It also grants the ShareGate migration tool rights to use certain Microsoft functionality, such as the Graph API. You need to update to version 12.0 or higher to have access to the Azure app.
For more information, see What is the Azure the ShareGate migration tool application?
The cause and effect of throttling
The ShareGate migration tool's goal is to complete your migration simply and efficiently - and that means processing requests as fast as possible.
Due to this, there might be a heavy load on your tenant that contributes to throttling. However, the migration procedure alone is not usually the sole cause of the throttling. Often, the amount of users on your tenant during business hours generates a significant load as well. Other causes, such as backup applications running simultaneously to the ShareGate migration tool contribute to the strain as well.
Reducing the load to prevent throttling
The best way to prevent throttling is to schedule large migration procedures outside of business hours (overnight or weekends are ideal).
If you are dealing with a business that runs across different time zones (thus eliminating the opportunity to run the migration with low server load), review the applications that use your tenant to run. Limiting background application activity during the migration procedure reduces the chance of throttling.
If neither of those options is possible, it may be best to split a large migration into smaller intervals. Migrate a bit at a time, and the request load on the server will be significantly less.
You can check out Microsoft's SharePoint Online and OneDrive Migration Speed article for information on the factors that affect migration speed and some best practices.
Throttling may cause frustration, but at the end of the day, it means that your Microsoft 365 tenant is being used to its full potential.
Experiencing some throttling is normal, but significant throttling indicates an issue. Significant throttling consists of more than 30% of requests being throttled for a period of 30 minutes or more.
How we help
As an approved Microsoft partner and vendor, the ShareGate migration tool follows best practices recommended by Microsoft to reduce throttling. These include the following:
- We decorate HTTP traffic with an ISV Identifier that is well known by Microsoft.
- We handle throttling errors directly through the app.
- We use a retry policy in throttling situations that follow Microsoft directives.
- We inform you when throttling is happening frequently enough to cause a significant delay in your operations (via the error).
- We offer users the chance to consent to the Azure ShareGate migration tool app (on ShareGate version 12.0 or higher), which can effectively limit throttling.